Hydraulic work holder



Ja 9, 1945. J. T. OBECNY HYDRAULIC WORK HOLDER Filed April 17, 1943 4 Sheets-Sheet 1 IN VEN TOR. 0572 05 e c 79 3 Kim BY Jan. 9, 1945. J. T. OBECNY 2,366,979

HYDRAULIC WORK HOLDER Filed April 17, 1943 4 Sheets-Sheet 2 Jan. 9, 1945. .1. T. OBECNY 2,366,979

HYDRAULIC WORK HOLDER Filed April 1'7, 1943 4 Sheets-Sheet 5 I N VEN TOR.

fiforney 23%,919 RAULIG WORK HOWER liohn T. @hecny. one-half to Qaliii.

application it Claims.

This invention draulic work holders and more particularly to that type by which work pieces are effectively held in position for multiple chucking in milling machines, shapers, drill presses, grinding machines, etc. More particularly this invention relates to improvements upon the construction set forth in my companion Serial Number 354,597, filed August 28, 2,339,799), and Serial Number 405,319, gust 4, 1941, (Patent No. 2,339,800), of which the present application is a continuation in part. This invention like in the structure set forth in said applications is adapted for multiple production oi fine precision work and a number or work pieces are held firmly and evenly by applied pressure regardless of inequalities, the controlled pressure elements being equalized to apply even pressure simultaneously upon a number of work pieces. The invention is further simplified and made more efiective by the use oi a single applicator or plunger unit for operating a plurality of work piece clamping collets in the holder, simultaneously. A series of said units is provided while the individual collets thereof are arranged in a plurality of rows and the pressure for actuating all of, the collets is evenly distributed and equalized. One of the objects attained by the present improvement is the production or an apparatus by which no single work piece is permitted to slip while being machined or worked in Among further objects and advantages is the saving of time and expense in the multiple production of machined articles and the correct and accurate positioning of the work pieces for milling. grinding, cutting or other working.

With the above objects and advantages in view, in addition to and including the principal objects and advantages set forth in. my companion applications, my invention comprises the features of construction and combination of parts hereinafter described and claimed.

In the accompanying drawings, forming part of this specification, Fig. 1 is a front elevational view of my improved work holder; Fig. 2 is a plan of the structure shown in Fig. 1, a portion of the body being broken away to illustrate more clearly, one tandem pair of collets and actuating unit; Fig. 3 is an enlarged vertical section or a detail, taken approximately on the line 3--3 of Fig. 2, the plungers 20 and 2|, collet B and plug 29 being shown in full; Fig. 4 is a section taken on the line 4-4 of Fig. 3, the plunger mechanism, collets B and plug 29 being shownin-f ull;

Les Angclee, Calm, assignor at Morrison 0. Gar-st,

Sacramento,

April 17, 1943, Serial No. 4835M Fig. 5 is a diagram or schematic view showing my improved work holder, and illustrating the operation or the work holding spring collets and the cooperating hydraulic actuators by which the collets are caused to function simultaneously, and particularly the tandem arrangement by which the construction is simplified and the propelling force is distributed evenly to all of the collets; Fig. 6 is a plan of a detail of my improved work holder showing an alternative construction, a portion of the section and disclosing two of the work piece holding collets and a single laterally disposed plunger unit for hydraulically actuating a pair or the collets simultaneously; Fig. 7 is a section taken on the line 1-4 of Fig. 6, the collet B and plunger unit being shown in full, and Fig. 8 is a section of a detail taken on the line 8-3 of Fig. 7, the

plunger ti and equalizing head at being shown in iull.

My improvement relates more particularly to the use of a single actuating unit C for simultane ously operating a plurality or pair of work piece holding collets B, thereby simplifying the construction and reducing the cost of production while improving the operation. This improvement is used in a work holding body A and with a suitable source or hydraulic compression means such as is disclosed in my companion applicaidentified. The body and hydraulic actuating means will therefore be described only briefly. For more specific description reference is made to said applications.

A is a suitable body or housing in which collets B are held in corresponding chucks or chuck openings It. These chucks and collets are arranged in two or more parallel rows with each pair of collets and chucks co-axialand substantially vertical when the body assumes'upright position. The collets are supported with their upper ends in substantially a horizontal plane. AS shown their upper ends are flush with the surface or the body. The collets in the chucks are arranged closely in each row, thus work in the correct position for double milling or other operation, a minimum of loss of milling or other work. y A is substantially rectangular or oblong and is provided with suitable horizontal and vertical bosses l i by which it may be bolted or clamped incorrect position on a machine or other support, with the work pieces such as D (Fig. 5), held securely and in substantial alignment, whereby a number or the work pieces can be machined or worked simultanecusly with maximum precision. Each collet lower end of each chuck It. Various types of M which are separated by a gap so that the sleeve can be contracted and wrapped tightly around the body or stem of the work piece in the collet. A pair of vertical channels is weaken the collet body so as to assist in permitting seat 28, which is pro-. vided by the wall of the chuck in the body A so that when the plunger 2i is urged forwardly by hydraulic pressure the flexible arm 14 is wrapped working loose. each actuating unit is thus the plug 29. By removing compressed simultaneously 2,368,979 is supported on an annular shoulder 12 in the and parts of the accompanying actuating unit can be removed or replaced in the body. Repairof the parts is thus facilitated.

pump E. (see Fig. 5), in a similar manner to that set forth in my companion applications above identified. The circuit of the propelling fluid is illustrated diagramency of the coliets for a period sufllcient to roachine or otherwise work the articles which are held by the dev'ce, and for releasing the ccllets row as may be structure.

By arranging the collets in a double row with a single hydraulic actuating unit for each transverse pair of collets, the construction is simplified and its relative cost of production reduced to a minimum The output of work is increased and the device otherwise materially improved in efficiency and effectiveness. Equalization of the hydraulically driven pressure elements applied to the collets also serves to hold all of the work pieces evenly and rigidly so as to overcome all inequalities while being machined or worked. Also by arranging the collets in two parallel rows, double milling, machining or other work operations can be performed, thus reducing time, expense and efiort of production.

In the alternative construction illustrated ,in Figs. 6 to 8 inclusive, two adjacent collets are shown operated by a single actuator instead of a tandem arrangement of plungers as above described. The construction however is equally applicable for use with a multiple tandem arrangement when desired. The improvement provides the compressible collets B whose axes are parallel and whose longitudinal gaps I of each pair face each other These'collets are held in a corresponding pair of chucks 50, in a suitable body F. A single cylindrical plunger 5| is reciprocable in a cylindrical bore 52, said parts being disposed in the body F in a line substantially transverse to the axes of the collets. The plunger element carries an equalizing head 53 which has a pair of forwardly converging faces 54, said faces being adapted to bear with a guiding movement against the sides of the resilient arms 55 and compress the collets by wrapping the bodies or stems of the work pieces 65 and holding them firmly. The equalizing head is slightly less in diameter than the diameter of the bore 52 to allow free movement of the head and permit even application of the operating force against the collets during the advancing movement of. the plunger. A single plug 56 is inserted and held in the bore 52 ahead of the collets by the pin 57. This plug functions to close the bore 52 and may when desired be used as a seat forthe arms 58 of the collet. Keys 59 seated in the body F and engaging the collets in weakening slots 50, as in t e preferred construction, serve to prevent rotary movement of the collets in their seats. The return movement of the plunger 5! into normal releasing position of the collets is produced by the helical expansion spring 6| (Fig. 8), which bears against lock nuts 62 which are threaded upon the stem 53 of the plunger, at one end and against the inner shoulder of a cupped nut 64, at its opposite end. The cupped nut is threadedly engaged in a suitable recess 85 in the body F.

When fluid in the bore 52 back of the plunger is compressed, the plunger is urged forwardly and compresses the pair of collets simultaneously, the collets in turn engaging the body or shank of the work piece 66 by wrapping. As many of these units, each composed of a pair of collets and a single actuating plunger are incorporated into a single body F, as desired, the several units being connected by a manifold passage 61 witha suitably controlled source of hydraulic pressure for equalizing the distribution of the compressed fluid medium to all of the actuating elements.

The construction permits of assembling all of the collets in a single or multiple rows or in any other convenient position desired.

In accordance with the patent statutes, I have described the principles of operation of my invention, together with the construction thereof which I now consider to represent the best em-.

bodiment thereof, but I desire to have it understood that the construction shown is only illusnative and that the invention can be carried out by other means and applied to uses other than those above set forth without departing from the spirit of the invention and within the scope of the following claims.

I claim: I

1. In a holder for a plurality of work pieces, the combination ofa body having a pair of collet seats therein, a contractible collet mounted in each seat having a socket for receiving a work piece, a pressure element guided toward and simultaneously against the walls of both collets, said pressure element and said collets having engaging faces cooperating to contract both collets simultaneously and clamp their corresponding work pieces, and means for actuating the pressure element against said collets.

2. In a holder for a plurality of work pieces, the combination of a body having a pair of closely associated collet seats, a contractible collet mounted in each seat having a socket for receiving a work piece, a pressure element corresponding with said collets and guided to move toward and simultaneously against the walls of both collets along a line substantially transverse to the longitudinal axes of the collets, said pressure element and said collets having engaging faces cooperating to compress the collets simultaneously and clamp their corresponding work pieces, and hydraulic means for advancing the pressure element.

3. In a hydraulic work holder, a body having aligned chucks to receive collets, corresponding collets seated in said chucks for holding work pieces, pressure units corresponding with and hydraulically operable between the members of each pair of said collets for compressing the collets upon work pieces therein, the members of each pair of collets and their corresponding compression unit having engaging faces cooperating to contract the collets and engage their companion work pieces, hydraulicmeans for operating said pressure units upon the members of each pair of collets simultaneously, said hydraulic means being common to all of the collets, and manually operable means for controlling said hydraulic means, whereby the pressure is equalized on all of the collets.

4. In a hydraulic work holder, a body having a pair of chucks, corresponding contractible collets seated in said chucks for holding work pieces, a pressure unit freely operable between said collets for compressing the same upon work pieces therein, means for operating said pressure unit upon both of said collets-simultaneously, said operating means being common to both of said collets, and means for controlling said operating means, whereby the pressure is equalized on both of said collets. v

5. In a holder for a plurality of work pieces, the combination of a body having a plurality of collet seats, arranged in a plurality of rows, the collet seats of companion rows being arranged in transverse pairs, a contractible collet mounted in each set and having a socket for receiving a work piece, a pressure unit guided to move simultaneously toward and against the walls of the collets of each pair along a line substantially transverse to the longitudinal axes of the collets, the collets of each pair and their corresponding pressure unit having engaging faces cooperating to compress the collets and grip work pieces therein, and means for actuating the pressure units in unison to contract the collets.

6. A hydraulic work holder including in combination, a body having a plurality of substantially parallel rows of collet seats arranged in transverse pairs between said rows, a corresponding series of collets held in said seat for holding work pieces, a pressure element for each transverse pair of collets hydraulically operable for simultaneously compressing the members of each pair upon work pieces, hydraulic means for simultaneously operating said pressure elements in cooperation with said collets, said hydraulic means being common to all of said pressure elements, whereby pressure is equalized on all of said collets, and manually operable means forcontrolling said hydraulic means.

7. A hydraulic work holder including in combination, a body having a series of transverse pairs of chucks for seating collets, contractible work piece receiving collets seated in said chucks, corresponding pressure units simultaneously cooperating to operate the collet members of each of said pairs, hydraulic means for actuating said pressure units to compress each pair of collets simultaneously, said hydraulic mean being com, mon to all of said pressure units whereby pressure is equalized on all of said collets, and means for controlling said hydraulic means.

8. A hydraulic work holder including in combination, a body having a series or chucks arranged in pairs for seating collets, contractible work piece receiving collets seated in said chucks, corresponding pressure units equalized between the collet members of each pair, hydraulic means for actuating said pressure units to compress each pair of collets simultaneously, said hydraulic means being common to all of said pressure units, whereby pressure is equalized on all of said collets, and means for controlling said hydraulic means.

9. A hydraulic work holder including in corn: bination, a body having a series of chucks ar ranged in pairs for seating collets, contractibie work piece engaging collets seated in said chucks, a pressure unit cooperating with each pair of collet members, means by which the pressure imparted by the pressure unit is equalized against the members of the companion pair of collets, bydraulic means for actuating said pressure units to compress all of the pairs of collets simultaneously, said hydraulic means being common to all of said pressure units, whereby pressure is equalized on all of said collets, and means for controlling said hydraulic means.

10. In a work holder, a body having a pair of contractible chuck elements, a pressure unit freely operable between said chuck elements for compressing the same upon work pieces therein, means for operating said pressure unit upon both of said chuck elements simultaneously, said operating means being common to both of said chuck elements, and means for controlling said operating means whereby the pressure is equalized on both of said chuck elements.

JOHN T. OBECNY. 

